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This repository is a mirror of https://git.openwrt.org/openwrt/openwrt.git It is for reference only and is not active for check-ins. We will continue to accept Pull Requests here. They will be merged via staging trees then into openwrt.git.
7b4877c204
While the other fq-based qdiscs take advantage of skb->hash and doesn't recompute it if it is already set, sch_cake does not. This was a deliberate choice because sch_cake hashes various parts of the packet header to support its advanced flow isolation modes. However, foregoing the use of skb->hash entirely loses a few important benefits: - When skb->hash is set by hardware, a few CPU cycles can be saved by not hashing again in software. - Tunnel encapsulations will generally preserve the value of skb->hash from before the encapsulation, which allows flow-based qdiscs to distinguish between flows even though the outer packet header no longer has flow information. It turns out that we can preserve these desirable properties in many cases, while still supporting the advanced flow isolation properties of sch_cake. This patch does so by reusing the skb->hash value as the flow_hash part of the hashing procedure in cake_hash() only in the following conditions: - If the skb->hash is marked as covering the flow headers (skb->l4_hash is set) AND - NAT header rewriting is either disabled, or did not change any values used for hashing. The latter is important to match local-origin packets such as those of a tunnel endpoint. The immediate motivation for fixing this was the recent patch to WireGuard to preserve the skb->hash on encapsulation. As such, this is also what I tested against; with this patch, added latency under load for competing flows drops from ~8 ms to sub-1ms on an RRUL test over a WireGuard tunnel going through a virtual link shaped to 1Gbps using sch_cake. This matches the results we saw with a similar setup using sch_fq_codel when testing the WireGuard patch. Fixes: 046f6fd5daef ("sched: Add Common Applications Kept Enhanced (cake) qdisc") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> |
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_______ ________ __ | |.-----.-----.-----.| | | |.----.| |_ | - || _ | -__| || | | || _|| _| |_______|| __|_____|__|__||________||__| |____| |__| W I R E L E S S F R E E D O M ----------------------------------------------------- This is the buildsystem for the OpenWrt Linux distribution. To build your own firmware you need a Linux, BSD or MacOSX system (case sensitive filesystem required). Cygwin is unsupported because of the lack of a case sensitive file system. You need gcc, binutils, bzip2, flex, python3.5+, perl, make, find, grep, diff, unzip, gawk, getopt, subversion, libz-dev and libc headers installed. 1. Run "./scripts/feeds update -a" to obtain all the latest package definitions defined in feeds.conf / feeds.conf.default 2. Run "./scripts/feeds install -a" to install symlinks for all obtained packages into package/feeds/ 3. Run "make menuconfig" to select your preferred configuration for the toolchain, target system & firmware packages. 4. Run "make" to build your firmware. This will download all sources, build the cross-compile toolchain and then cross-compile the Linux kernel & all chosen applications for your target system. Sunshine! Your OpenWrt Community http://www.openwrt.org